Switching period symbol position for receiver switching

Abstract

A method for wireless communication by a user equipment (UE) includes: receiving a receive chain switching configuration for a multi-carrier environment from a base station. The UE also utilizes multiple receive chains to receive a physical downlink control channel (PDCCH) on one or more carriers in the multi-carrier environment according to the receive chain switching configuration. The UE decodes downlink control information (DCI) for physical downlink shared channel (PDSCH) scheduling across multiple carriers in the multi-carrier environment from the PDCCH. The UE performs receive chain switching based on the PDSCH scheduling and the receive chain switching configuration from the decoded DCI.

Description

Technical Field

[0001] Generally speaking, aspects of the present disclosure relate to wireless communications, and more particularly, to techniques and apparatus for 5G New Radio (NR) switching period symbol positions for receiver (Rx) switching. Background Art

[0002] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0003] A wireless communication network may include multiple base stations (BSs) that can support communications for multiple user equipments (UEs). User equipments (UEs) may communicate with base stations (BSs) via downlinks and uplinks. A downlink (or forward link) refers to a communication link from a BS to a UE, and an uplink (or reverse link) refers to a communication link from a UE to a BS. As will be described in more detail, a BS may be referred to as a Node B, gNB, access point (AP), radio head, transmit and receive point (TRP), new radio (NR) BS, 5G Node B, etc.

[0004] The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user devices to communicate at city, country, region, and even global levels. New Radio (NR) (which may also be referred to as 5G) is an enhancement set of the LTE mobile standard released by the Third Generation Partnership Project (3GPP). NR is designed to better integrate with other open standards by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and using orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with cyclic prefix (CP) on the downlink (DL), using CP-OFDM and / or SC-FDM (e.g., also referred to as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), and supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation, so as to better support mobile broadband Internet access.

[0005] UE can support high rank transmission (e.g., a larger number of receiving chains) at higher frequency bands because additional resources are available.UE can support low or high rank transmission (e.g., a smaller or larger number of receiving chains, such as one or two receiving chains) at low frequency bands because, for example, there are fewer available resources and the low frequency band is advantageous for cell edge UEs. In addition, for UEs with reduced capabilities (which may be referred to as "RedCap UEs"), there may be only two receiving chains and three or four antennas. For example, a UE with reduced capabilities may be configured with one or two receiving chains and may switch between a high frequency band and a low frequency band. Unfortunately, since a UE with reduced capabilities may have fewer or less complex resources, the UE may not be able to simultaneously support two receiving chains (2Rx) reception on a high frequency band and one receiving chain (1Rx) or 2Rx reception on a low frequency band. Summary of the invention

[0006] In one aspect of the present disclosure, a method for wireless communication performed by a user equipment (UE) is provided. The method includes: receiving a receive chain switching configuration for a multi-carrier environment from a base station. The method also includes: using multiple receive chains to receive a physical downlink control channel (PDCCH) on one or more carriers in the multi-carrier environment according to the receive chain switching configuration. In addition, the method includes: decoding downlink control information (DCI) for physical downlink shared channel (PDSCH) scheduling across multiple carriers in the multi-carrier environment from the PDCCH. Further, the method includes: performing receive chain switching based on the PDSCH scheduling and receive chain switching configuration from the decoded DCI.

[0007] In another aspect of the present disclosure, a device for wireless communication performed by a user equipment (UE) is provided. The device includes a memory and one or more processors coupled to the memory. The processor is configured to: receive a receive chain switching configuration for a multi-carrier environment from a base station. The processor is also configured to: utilize multiple receive chains to receive a physical downlink control channel (PDCCH) on one or more carriers in the multi-carrier environment according to the receive chain switching configuration. In addition, the processor is configured to: decode downlink control information (DCI) for physical downlink shared channel (PDSCH) scheduling across multiple carriers in the multi-carrier environment from the PDCCH. Further, the processor is configured to: perform receive chain switching based on PDSCH scheduling and receive chain switching configuration from the decoded DCI.

[0008] In another aspect of the present disclosure, a device for wireless communication by a user equipment (UE) is provided. The device includes: a unit for receiving a receive chain switching configuration for a multi-carrier environment from a base station. The device also includes: a unit for receiving a physical downlink control channel (PDCCH) on one or more carriers in the multi-carrier environment using multiple receive chains according to the receive chain switching configuration. The device further includes: a unit for decoding downlink control information (DCI) for physical downlink shared channel (PDSCH) scheduling across multiple carriers in the multi-carrier environment from the PDCCH. In addition, the device includes: a unit for performing receive chain switching based on the PDSCH scheduling and receive chain switching configuration from the decoded DCI.

[0009] In another aspect of the present disclosure, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium has a program code recorded thereon for wireless communication by a user equipment (UE). The program code is executed by the UE and includes: a code for receiving a receive chain switching configuration for a multi-carrier environment from a base station. The program code also includes: a code for receiving a physical downlink control channel (PDCCH) on one or more carriers in a multi-carrier environment using multiple receive chains according to the receive chain switching configuration. The program code further includes: a code for decoding downlink control information (DCI) for physical downlink shared channel (PDSCH) scheduling across multiple carriers in a multi-carrier environment from the PDCCH. In addition, the program code includes: a code for performing receive chain switching based on the PDSCH scheduling and receive chain switching configuration from the decoded DCI.

[0010] The aspects generally include methods, apparatus, systems, computer program products, non-transitory computer readable media, user equipment, base stations, wireless communication devices, and processing systems as fully described with reference to and as illustrated by the drawings and description.

[0011] The foregoing has outlined the features and technical advantages of examples according to the present disclosure in a rather broad manner so that the detailed description below may be better understood. Additional features and advantages will be described. The disclosed concepts and specific examples may be easily used as the basis for modifying or designing other structures for the same purpose of achieving the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. When considered in conjunction with the accompanying drawings, the characteristics of the disclosed concepts (both their organization and method of operation) and the associated advantages will be better understood according to the following description. Each of the figures in the accompanying drawings is provided for the purpose of illustration and description and is not intended to be a definition of limitations to the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to fully understand the features of the present disclosure, a specific description may be obtained by reference to various aspects, some of which are shown in the accompanying drawings. However, it should be noted that the drawings only illustrate certain aspects of the present disclosure and are therefore not to be considered as limiting the scope of the present disclosure, as the specification may admit other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0013] Figure 1 is a block diagram conceptually illustrating an example of a wireless communication system in accordance with various aspects of the present disclosure.

[0014] Figure 2 is a block diagram conceptually illustrating an example of a base station in communication with a user equipment (UE) in a wireless communication network according to various aspects of the present disclosure.

[0015] Figure 3A , 3B , 3C, and 3D are schematic diagrams showing examples of a first fifth generation (5G) new radio (NR) frame, a downlink (DL) channel within a 5G NR subframe, a second 5G NR frame, and an uplink (UL) channel within a 5G NR subframe, respectively.

[0016] Figure 4A and 4B is a schematic diagram illustrating an example receive chain configuration of a user equipment (UE) in accordance with aspects of the present disclosure.

[0017] Figure 4C is a table listing example configurations for time division multiplexing (TDM) downlink (DL) carrier aggregation (CA) in accordance with aspects of the present disclosure.

[0018] Figure 5A is a schematic diagram illustrating an example of cross-carrier scheduling according to aspects of the present disclosure.

[0019] Figure 5B is a schematic diagram illustrating an example of self-carrier scheduling according to aspects of the present disclosure.

[0020] Fig. 6A and 6B is a schematic diagram illustrating an example of cross-carrier scheduling according to aspects of the present disclosure.

[0021] Fig. 7A and 7B is a schematic diagram illustrating an example of self-carrier scheduling according to aspects of the present disclosure.

[0022] Figure 8 is a schematic diagram illustrating a downlink reception period according to aspects of the present disclosure.

[0023] Fig. 9 is a diagram illustrating example processes performed, for example, by a user equipment (UE) according to various aspects of the present disclosure. DETAILED DESCRIPTION

[0024] The various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure can be embodied in many different forms, and should not be interpreted as being limited to any specific structure or function presented throughout the present disclosure. Specifically, these aspects are provided so that the present disclosure will be comprehensive and complete, and the scope of the present disclosure will be fully conveyed to those skilled in the art. Based on teachings, those skilled in the art should recognize that the scope of the present disclosure is intended to cover any aspect of the present disclosure, regardless of whether the aspect is implemented independently of any other aspect of the present disclosure or implemented in combination with any other aspect. For example, any number of aspects described can be used to implement a device or a method can be practiced. In addition, the scope of the present disclosure is intended to cover such a device or method that is practiced using other structures, functions, or structures and functions in addition to or different from the various aspects of the disclosed content described. It should be understood that any aspect of the disclosed disclosure can be embodied by one or more elements of the claim.

[0025] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0026] It should be noted that while various aspects may be described using terminology commonly associated with 5G and beyond wireless technologies, various aspects of the present disclosure may be applicable to communication systems based on other generations, such as and including 3G and / or 4G technologies.

[0027] The UE may be configured to support high rank transmissions (e.g., a larger number of receiving chains) at higher frequency bands because additional resources are available. The UE may support low or high rank transmissions (e.g., a smaller or larger number of receiving chains, such as one or two receiving chains) at low frequency bands because, for example, there are fewer available resources and the low frequency band is advantageous for cell edge UEs. In addition, some UEs may have reduced capabilities. These reduced-capability UEs (which may be referred to as "RedCap UEs") may be characterized by lower complexity and reduced energy consumption compared to other UEs. Reduced-capability UEs may include NR light UEs and Internet of Things (IoT) devices. In one example, a UE with reduced capabilities may be configured with only two receiving chains and three or four antennas. For example, a reduced-capability UE may be configured with one or two receiving chains and may switch between high and low frequency bands. Unfortunately, since the reduced-capability UE may have fewer or less complex resources, the UE may not be able to simultaneously support two receiving chains (2Rx) reception on the high frequency band and one receiving chain (1Rx) or 2Rx reception on the low frequency band.

[0028] Various aspects of the present disclosure relate to a switching period position for scheduling reception of a physical downlink shared channel (PDSCH) across multiple component carriers in a carrier aggregation environment. In some aspects, the switching period or position can be configured for simultaneously receiving a physical downlink control channel (PDCCH) on multiple carriers for decoding downlink control information (DCI) for PDSCH scheduling across multiple carriers. DCI provides information to the UE, such as physical layer resource allocations, power control commands, and other control information.

[0029] Figure 1 1 is a schematic diagram showing a network 100 in which various aspects of the present disclosure may be practiced. The network 100 may be a 5G or NR network or some other wireless network (such as an LTE network). The wireless network 100 may include a plurality of BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with a user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, transmit and receive point (TRP), etc. Each BS may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to a coverage area of ​​a BS and / or a BS subsystem serving the coverage area, depending on the context in which the term is used.

[0030] A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and / or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1 In the example shown in , BS 110a may be a macro BS for macro cell 102a, BS 110b may be a pico BS for pico cell 102b, and BS 110c may be a femto BS for femto cell 102c. A BS may support one or more (e.g., three) cells. The terms “eNB,” “base station,” “NR BS,” “gNB,” “TRP,” “AP,” “Node B,” “5G NB,” and “cell” may be used interchangeably.

[0031] In some aspects, the cells may not necessarily be stationary, and the geographic area of ​​the cells may move depending on the location of the mobile BS. In some aspects, the BSs may be interconnected with each other and / or with one or more other BSs or network nodes (not shown) in the wireless network 100 via various types of backhaul interfaces (e.g., direct physical connections, virtual networks, etc.) using any appropriate transport network.

[0032] The wireless network 100 may also include a relay station. A relay station is an entity that can receive transmissions of data from an upstream station (e.g., a BS or a UE) and send transmissions of data to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. Figure 1 In the example shown in FIG. 1 , a relay station 110 d may communicate with a macro BS 110 a and a UE 120 d to facilitate communication between the BS 110 a and the UE 120 d. A relay station may also be referred to as a relay BS, a relay base station, a relay, or the like.

[0033] The wireless network 100 may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless network 100. For example, a macro BS may have a high transmit power level (e.g., 5 to 40 watts), while a pico BS, a femto BS, and a relay BS may have a lower transmit power level (e.g., 0.1 to 2 watts).

[0034] For example, BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and core network 130 may exchange communications via backhaul links 132 (e.g., S1, etc.). Base stations 110 may communicate with each other directly or indirectly (e.g., through core network 130) through other backhaul links (e.g., X2, etc.).

[0035] The core network 130 may be an evolved packet core (EPC), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may be a control node that processes signaling between the UE 120 and the EPC. All user IP packets may be transmitted through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation and other functions. The P-GW may be connected to the IP services of the network operator. The IP services of the operator may include the Internet, the intranet, the IP multimedia subsystem (IMS), and the packet switched (PS) streaming services.

[0036] The core network 130 may provide user authentication, access authorization, tracking, IP connectivity, and other access, routing, or mobility functions. One or more of the base stations 110 or access node controllers (ANCs) may interface with the core network 130 via a backhaul link 132 (e.g., S1, S2, etc.) and may perform radio configuration and scheduling to communicate with the UE 120. In some configurations, the various functions of each access network entity or base station 110 may be distributed across various network devices (e.g., radio heads and access network controllers) or merged into a single network device (e.g., base station 110).

[0037] UE 120 (e.g., 120a, 120b, 120c) can be dispersed throughout the wireless network 100, and each UE can be stationary or mobile. UE can also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. UE can be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet device, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or apparatus, a biometric sensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet, etc.)), an entertainment device (e.g., a music or video device, or a satellite wireless unit, etc.), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing device, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0038] One or more UEs 120 may establish a protocol data unit (PDU) session for a network slice. In some cases, the UE 120 may select a network slice based on an application or subscription service. By having different network slices serving different applications or subscriptions, the UE 120 may improve its resource utilization in the wireless communication network 100 while also meeting the performance specifications of the respective applications of the UE 120. In some cases, the network slice used by the UE 120 may be provided by an AMF (AMF) associated with one or both of the base station 110 or the core network 130. Figure 1 In addition, session management of the network slice can be performed by the access and mobility management function (AMF).

[0039] UE 120 may include a receive (Rx) switching module 140. For simplicity, only one UE 120d is shown as including the Rx switching module 140. The Rx switching module 140 may receive a receive chain switching configuration for a multi-carrier environment from a base station. The Rx switching module 140 may also utilize multiple receive chains to receive a physical downlink control channel (PDCCH) on at least one carrier in the multi-carrier environment according to the receive chain switching configuration. In addition, the Rx switching module 140 may decode downlink control information (DCI) for physical downlink shared channel (PDSCH) scheduling across multiple carriers in the multi-carrier environment from the PDCCH. In addition, the Rx switching module 140 may perform receive chain switching based at least in part on the PDSCH scheduling and receive chain switching configuration from the decoded DCI.

[0040] Some UEs may be considered as machine type communication (MTC) or evolved or enhanced machine type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc. that can communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node may provide a connection to a network (e.g., a wide area network such as the Internet or a cellular network) or a connection to a network, for example, via a wired or wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices, and / or may be implemented as NB-IoT (narrowband Internet of Things) devices. Some UEs may be considered as customer premises equipment (CPE). UE 120 may be included inside a housing that houses components of UE 120 (e.g., processor components, memory components, etc.).

[0041] Generally, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific radio access technology (RAT) and can operate on one or more frequencies. RAT can also be referred to as radio technology, air interface, etc. Frequency can also be referred to as carrier, frequency channel, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0042] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using base station 110 as an intermediary for mutual communication). For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocol (e.g., which may include vehicle-to-vehicle (V2V) protocol, vehicle-to-infrastructure (V2I) protocol, etc.), mesh network, etc. In this case, UE 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere as being performed by base station 110. For example, base station 110 may configure UE 120 via downlink control information (DCI), radio resource control (RRC) signaling, medium access control-control element (MAC-CE), or via system information (e.g., system information block (SIB)).

[0043] As pointed out above, Figure 1 This is provided only as an example. Other examples may differ from those described above. Figure 1 as described.

[0044] Figure 2 Base station 110 and UE 120 (which may be Figure 1 1. Block diagram of a design 200 of a base station in a base station and a UE in a UE. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general, T≥1 and R≥1.

[0045] At the base station 110, the transmit processor 220 may receive data for one or more UEs from the data source 212, select one or more modulation and coding schemes (MCS) for the UE based at least in part on a channel quality indicator (CQI) received from each UE, process (e.g., encode and modulate) the data for the UE based at least in part on the MCS selected for each UE, and provide data symbols for all UEs. Reducing the MCS reduces throughput but increases the reliability of transmission. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.), and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols, if applicable, and may provide T output symbol streams to T modulators (MOD) 232a to 232t. Each modulator 232 may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a to 232t may be transmitted via T antennas 234a to 234t, respectively. According to various aspects described in more detail below, a synchronization signal may be generated using position coding to transmit additional information.

[0046] At UE 120, antennas 252a to 252r may receive downlink signals from base station 110 and / or other base stations, and may provide received signals to demodulators (DEMOD) 254a to 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 may obtain received symbols from all R demodulators 254a to 254r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. Receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to data sink 260, and provide decoded control information and system information to controller / processor 280. The channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of UE 120 may be included in a housing.

[0047] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information from a controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 (if applicable), further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by the antenna 234, processed by the demodulator 254, detected by the MIMO detector 236 (if applicable), and further processed by the receive processor 238 to obtain decoded data and control information transmitted by the UE 120. The receive processor 238 may provide decoded data to a data sink 239 and provide decoded control information to a controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the core network 130 via the communication unit 244. The core network 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0048] A controller / processor of UE 120 and / or Figure 2Any other components in the UE 120 may perform one or more techniques associated with the switching period symbol position for receiver (Rx) switching, as described in more detail elsewhere. For example, the controller / processor 280 and / or Figure 2 Any other component may perform or direct e.g. Fig. 9 The processes and / or operations of other processes as described. Memories 242 and 282 may store data and program codes for base station 110 and UE 120, respectively. Scheduler 246 may schedule UEs for data transmission on the downlink and / or uplink.

[0049] In some aspects, the UE 120 may include a unit for receiving a receive chain switching configuration for a multi-carrier environment from a base station. The UE 120 may also include a unit for receiving a physical downlink control channel (PDCCH) on at least one carrier of the multi-carrier environment using multiple receive chains according to the receive chain switching configuration. The UE 120 may also include a unit for decoding downlink control information (DCI) for physical downlink shared channel (PDSCH) scheduling across multiple carriers in the multi-carrier environment from the PDCCH. In addition, the UE 120 may include a unit for performing receive chain switching based on the PDSCH scheduling and the receive chain switching configuration from the decoded DCI. Such a unit may include a combination of Figure 2 One or more components of UE 120 are described.

[0050] As pointed out above, Figure 2 This is provided only as an example. Other examples may differ from those described above. Figure 2 as described.

[0051] Figure 3A is a diagram 300 showing an example of a first subframe within a 5G NR frame structure. Figure 3B is a schematic diagram 330 showing an example of DL channels within a 5G NR subframe. Figure 3C is a diagram 350 showing an example of a second subframe within a 5G NR frame structure. Figure 3D 380 is a diagram showing an example of UL channels within a 5G NR subframe. The 5G NR frame structure can be frequency division duplex (FDD) (wherein, for a particular set of subcarriers (carrier system bandwidth), a subframe within a subcarrier set is dedicated to either DL or UL), or can be time division duplex (TDD) (wherein, for a particular set of subcarriers (carrier system bandwidth), a subframe within a subcarrier set is dedicated to both DL and UL). Figure 3A , 3CIn the example provided, the 5G NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (most of which are DL), where D is DL, U is UL, and X is flexible between DL / UL, and subframe 3 is configured with slot format 34 (most of which are UL). Although subframes 3 and 4 are shown as having slot formats 34 and 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and full UL, respectively. Other slot formats 2-61 include a mix of DL, UL and flexible symbols. The UE is configured with a slot format (dynamically configured by DL control information (DCI) or semi-statically / statically configured by radio resource control (RRC) signaling) through the received slot format indicator (SFI). Note that the following description also applies to the 5G NR frame structure of TDD.

[0052] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 subframes (1ms) of equal size. Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4 or 2 symbols. Each time slot may include 7 or 14 symbols, depending on the time slot configuration. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. The symbol on the DL may be a cyclic prefix (CP) OFDM (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) spread OFDM (DFT-S-OFDM) symbol (also referred to as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-limited scenarios; limited to single stream transmission). The number of time slots within a subframe may be based on the time slot configuration and numerology. For slot configuration 0, different digital schemes μ0 to 5 allow 1, 2, 4, 8, 16 and 32 slots per subframe, respectively. For slot configuration 1, different digital schemes 0 to 2 allow 2, 4 and 8 slots per subframe, respectively. Accordingly, for slot configuration 0 and digital scheme μ, there are 14 symbols / slot and 2μ slots / subframe. The subcarrier spacing and symbol length / duration are functions of the digital scheme. The subcarrier spacing can be equal to 2^μ*15kKz, where μ is digital scheme 0 to 5. Therefore, digital scheme μ=0 has a subcarrier spacing of 15kHz, and digital scheme μ=5 has a subcarrier spacing of 480kHz. The symbol length / duration is negatively correlated with the subcarrier spacing. Figures 3A-3DAn example is provided for slot configuration 0 with 14 symbols per slot and a digital scheme μ = 0 with 1 slot per subframe. The subcarrier spacing is 15 kHz and the symbol duration is approximately 66.7 μs.

[0053] The resource grid may represent a frame structure. Each time slot includes a resource block (RB) (also referred to as a physical RB (PRB)), which includes 12 consecutive subcarriers. The resource grid is divided into a plurality of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0054] like Figure 3A As shown in , some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) for channel estimation at the UE (indicated as Rx for a specific configuration, where 100x is the port number, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS). The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0055] Figure 3B Examples of various DL channels within a subframe of a frame are shown. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including 4 consecutive REs in an OFDM symbol. The primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of a frame. The PSS is used by UE104 to determine subframe / symbol timing and physical layer identification. The secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the physical layer cell identification group number and radio frame timing. Based on the physical layer identification and the physical layer cell identification group number, the UE may determine the physical cell identifier (PCI). Based on the PCI, the UE may determine the location of the aforementioned DM-RS. The physical broadcast channel (PBCH), which carries the master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information not sent through the PBCH (such as System Information Blocks (SIBs)), and paging messages.

[0056] like Figure 3CAs shown in , some of the REs carry DM-RS for channel estimation at the base station (indicated as R for a specific configuration, but other DM-RS configurations are possible). The UE can send DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS can be sent in the first one or two symbols of the PUSCH. The PUCCH DM-RS can be sent in different configurations depending on whether a short PUCCH or a long PUCCH is sent and depending on the specific PUCCH format used. Although not shown, the UE can send a sounding reference signal (SRS). The SRS can be used by the base station for channel quality estimation to achieve frequency-related scheduling on the UL.

[0057] Figure 3D Examples of various UL channels within a subframe of a frame are shown. The PUCCH may be positioned as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and hybrid automatic repeat request (HARQ) acknowledgement / negative acknowledgement (ACK / ACK) feedback. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0058] Figure 4A and 4B is a schematic diagram illustrating an example receive chain configuration of a user equipment (UE) according to aspects of the present disclosure. Figure 4A , UE 400 includes two receive (Rx) chains (e.g., Rx chain 0 and Rx chain 1) and three antennas (e.g., high-band antenna 0, high-band antenna 1, and low-band antenna 1). Rx chain 0 uses high-band antenna 0. On the other hand, Rx chain 1 can switch between low-band or high-band communication on low-band antenna 1 or high-band antenna 1, respectively.

[0059] refer to Figure 4B , UE 420 includes two receive chains (e.g., Rx chain 0 and Rx chain 1) and four antennas (e.g., high-band antenna 1, high-band antenna 2, low-band antenna 1, and low-band antenna 2). In UE 420, each Rx chain in the Rx chain can switch between high-band or low-band communication. For example, Rx chain 0 can switch between a high-band antenna (e.g., high-band antenna 1) and a low-band antenna (e.g., low-band antenna 1). Similarly, Rx chain 1 can switch between a high-band antenna (e.g., high-band antenna 2) and a low-band antenna (e.g., low-band antenna 2).

[0060] Transmissions on the high or low frequency band for UE 400 and UE 420 may be semi-static (e.g., periodic) or dynamic based on scheduling (e.g., supplementary downlink (SDL), carrier aggregation (CA), evolved universal mobile telecommunications service (UMTS) terrestrial radio access network (E-UTRAN) new radio dual connectivity (EN-DC)) across two carriers via a base station (e.g., gNB). For example, the carriers may both be time division duplex (TDD) carriers, or may be one TDD carrier and one frequency division duplex (FDD) carrier.

[0061] Thus, in one aspect of the present disclosure, a receive switching pattern and carrier switching period configuration are disclosed. The receive switching pattern and carrier switching period may be configured by a base station (e.g., a gNB) through radio resource control (RRC) signaling or a medium access control-control element (MAC-CE). In some aspects, the receive switching pattern may include two receive chains configured to receive a physical downlink control channel (PDCCH) on one carrier for decoding downlink control information (DCI) for physical downlink shared channel (PDSCH) scheduling across two carriers.

[0062] Figure 4C 4 is a table 450 listing example configurations for time division multiplexing (TDM) downlink (DL) carrier aggregation (CA). Figure 4C , three example cases are shown for DL ​​CA in Table 450. For TDD+FDD CA in Case 1 (on the first component carrier (CC1)), the UE can receive up to two layers at the TDD carrier. In Case 2, the UE can receive one layer at the FDD carrier. For TDD+TDD (on the second component carrier (CC2)), three example cases are shown. In Case 1, the UE can receive up to two layers of transmissions on the first TDD carrier. In Case 2, the UE can receive up to two layers of transmissions on the second TDD carrier. In Case 3, the UE receives one layer of transmission from the first TDD carrier and one layer of transmission from the second TDD carrier. Therefore, the UE only needs two receive chains and can switch the receive chains across the two frequency bands to support TDM downlink carrier aggregation.

[0063] According to various aspects of the present disclosure, a reception switching mode or scheme may be defined. In some aspects, the reception switching mode may include a cross-carrier scheduling mode. In cross-carrier scheduling, two reception layers for PDCCH may be received on one carrier for decoding DCI for PDSCH scheduling across two carriers.

[0064] In some aspects, the receive switching mode may include a self-carrier scheduling mode. In the self-carrier scheduling mode, the two carriers each receive the PDCCH. In some aspects, the carriers may receive the PDCCH simultaneously. In this way, a receive layer for the PDCCH may be received on both carriers for decoding the DCI for the PDSCH scheduling across the two carriers.

[0065] Figure 5A 5 is an example diagram 500 illustrating cross-carrier scheduling according to aspects of the present disclosure. Figure 5A As shown, TDD carrier 1 utilizes two receive antennas to receive a PDCCH for scheduling a PDSCH that spans both TDD carrier 1 and TDD carrier 2. In time slots 0 and 1, TDD carrier 1 receives a PDCCH (502) for scheduling a PDSCH on carrier 1, while TDD carrier 2 does not receive a PDSCH. Because the scheduling is only on TDD carrier 1, no receive switching is performed in time slots 0 and 1, so no switching period is configured, and two receive chains are placed on TDD carrier 1. In time slot 2, the UE also receives a PDCCH on TDD carrier 1, but the PDCCH scheduling for PDSCH reception is on TDD carrier 2. Therefore, the UE switches the receive chain from TDD carrier 1 to TDD carrier 2. In order to allow sufficient time for carrier switching, a switching gap or period 504 can be inserted so that the PDSCH is scheduled to be received on TDD carrier 2 after the switching period 504. After receiving the PDSCH in time slot 2, the UE switches the receive chain from TDD carrier 2 to TDD carrier 1 to receive the next PDCCH (in time slot 3). In order to allow sufficient time for carrier switching (e.g., from TDD carrier 2 to TDD carrier 1), a switching gap or period 504 is also configured after the PDSCH reception in time slot 2.

[0066] In time slot 3, the UE receives a PDCCH on TDD carrier 1, which has a schedule for PDSCH reception on TDD carrier 2 in a special (S) time slot. The UE switches the two receive chains from TDD carrier 1 to TDD carrier 2. A switching gap or period 504 may be inserted before the PDSCH reception to accommodate the switch. However, since the special (S) time slot includes a guard symbol at the end of the downlink reception period during which no transmission is received, the UE may switch the two receive chains to TDD carrier 1, which does not include a switching period, and symbols for downlink transmission on TDD carrier 1 (e.g., time slot 4) may be read.

[0067] In time slot 6, TDD carrier 1 receives PDCCH again. However, in time slot 6, the scheduling is for the UE to receive PDSCH on both TDD carrier 1 and TDD carrier 2. That is, one layer can be received on each carrier. In this way, the UE switches a receiving chain from TDD carrier 1 to TDD carrier 2. In order to allow enough time for carrier switching (TDD carrier 1 to TDD carrier 2), a switching gap or period 504 is also configured to be before the PDSCH reception on TDD carrier 2 in time slot 6. After receiving the PDSCH in time slot 6, the UE switches the receiving chain from TDD carrier 2 to TDD carrier 1 to receive the next PDCCH (time slot 7). Therefore, there is another switching gap 504. Similarly, a switching gap 504 is provided before switching in time slot 7 for downlink reception during a special time slot (S).

[0068] Figure 5B is a schematic diagram illustrating an example of self-carrier scheduling according to various aspects of the present disclosure. Figure 5B , in time slot 0, the UE receives PDCCH simultaneously on two carriers (e.g., TDD carrier 1 and TDD carrier 2), with one receive chain on TDD carrier 1 and one receive chain on TDD carrier 2. In time slot 0, PDSCH is scheduled only on TDD carrier 1. The UE switches one receive chain from TDD carrier 2 to TDD carrier 1 to receive two layers of PDSCH on TDD carrier 1. To accommodate the switching of receive chains, a switching period 554 may be included before and after PDSCH reception. In time slot 1, the UE again receives PDCCH on two carriers, however, the UE receives one layer of PDSCH on TDD carrier 1 and one layer of PDSCH on TDD carrier 2. Because receive switching is not performed for PDSCH reception in time slot 1, no switching gap or period is configured.

[0069] In time slot 2, the UE receives PDCCH on both carriers for PDSCH scheduled only on TDD carrier 2. The UE switches one receive chain from TDD carrier 1 to TDD carrier 2 to receive two layers of PDSCH on TDD carrier 2.

[0070] The position of the switching period symbol may be semi-statically configured by radio resource control (RRC) signaling on a designated carrier of the two downlink carriers. In cross-carrier scheduling, for a downlink timeslot, the carrier switching period does not exist for every downlink reception period, for example, if a downlink timeslot on one carrier overlaps an uplink timeslot on another carrier.

[0071] Although Figure 5A and 5BA TDD configuration is involved, but an FDD configuration is also contemplated. In this case, all time slots are considered downlink time slots. That is, only downlink carriers are considered.

[0072] Fig. 6A and 6B 600 and 650 are schematic diagrams respectively illustrating examples of cross-carrier scheduling according to aspects of the present disclosure. Fig. 6A In , the frequency position of the switching period is semi-statically configured by RRC signaling on TDD carrier 2. In time slot 4, the downlink time slot of TDD carrier 1 overlaps with the uplink time slot of TDD carrier 2, so no carrier switching period is configured.

[0073] On the other hand, if there is a switching period, the switching period is placed on the first one or more downlink symbols and the last one or more downlink symbols of the downlink reception period. Fig. 6A As shown in FIG. 6 , in time slot 2, a UE operating in a cross-scheduling configuration receives a PDCCH on TDD carrier 1, which schedules two-layer PDSCH reception on TDD carrier 2. In this way, the UE switches two receive chains to TDD carrier 2. To accommodate the receive switching, a switching period 604 is placed on the first one or more downlink symbols and the last one or more downlink symbols of the downlink reception period of time slot 2 of TDD carrier 2.

[0074] For special time slots with cross scheduling, the switching period is only placed on one or more downlink symbols in front of the downlink reception period. Fig. 6A , for TDD carrier 2, in slot 3, the switching period 604 is placed only on the first one or more downlink symbols of the downlink reception period. The switching gap 604 is not included in the last one or more symbols because the special slot includes a gap period and an uplink symbol at the end of the special slot, during which the receive chain can switch.

[0075] refer to Figure 6B , the frequency position of the switching period is semi-statically configured by RRC signaling on TDD carrier 1. For example, in time slot 2, a UE operating using the cross scheduling scheme receives a PDCCH for two-layer PDSCH reception on TDD carrier 2 on TDD carrier 1. In this way, the UE switches two reception chains to TDD carrier 2. To accommodate the reception switching, the switching period 654 is placed on the first one or more downlink symbols and the last one or more downlink symbols of the downlink reception period of time slot 2 of TDD carrier 1.

[0076] Fig. 7A and 7B700 and 750 are schematic diagrams respectively illustrating examples of self-carrier scheduling according to aspects of the present disclosure. Fig. 7A In the case of switching, the frequency position of the switching period is semi-statically configured by RRC signaling on TDD carrier 2, and Figure 7B In the embodiment, the frequency position of the switching period is semi-statically configured by RRC signaling on TDD carrier 1. That is, the frequency position of the switching period is semi-statically configured on a specific carrier among the two downlink carriers.

[0077] In self-scheduling for downlink time slots, a carrier switching period does not exist for every downlink reception period, for example, if the UE is scheduled to receive rank 1 PDSCH on two carriers simultaneously. Fig. 7A and 7B 1. In time slot 1, the UE is scheduled to receive one layer of PDSCH simultaneously on TDD carrier 1 and TDD carrier 2. Thus, since one receive chain has been allocated to each TDD carrier, no switching period is configured for time slot 1.

[0078] However, if there is a switching period, the switching period may be placed on the first one or more downlink symbols and the last one or more downlink symbols of the downlink reception period. Fig. 7A , in time slot 2, the UE receives PDCCH (702) for two-layer PDSCH reception on TDD carrier 2 on TDD carrier 1 and TDD carrier 2. In this way, the RRC configuration may include a switching period 704 for the first one or more downlink symbols and the last one or more downlink symbols of the downlink reception period for time slot 2 on TDD carrier 2.

[0079] In some implementations, if the downlink on one carrier overlaps with the uplink time slot on another carrier, the switching period 704 is placed only on the last one or more downlink symbols of the downlink reception period. Fig. 7A , in time slot 4, the downlink time slot of TDD carrier 1 overlaps with the UL time slot of TDD carrier 2. Therefore, in the case where the switching period is configured for TDD carrier 2, the switching period 704 is only placed on the last one or more downlink symbols of the downlink reception period of TDD carrier 2. Similarly, referring to Figure 7B In time slot 4, in the case where a switching period is configured for TDD carrier 1, the switching period 754 is placed only on the last one or more downlink symbols of the downlink reception period of TDD carrier 1.

[0080] Furthermore, in some implementations, for a special time slot in the self-scheduling scheme, the switching period is only placed on one or more downlink symbols in front of the downlink reception period. Fig. 7A , in time slot 3, TDD carrier 2 has special (S) time slots in time slots 3 and 7. The switching period 704 is included only on the first one or more downlink symbols of the reception period.

[0081] The number of symbols included in the switching period to accommodate the reception switching from one carrier to another is determined based on the UE capabilities. For example, the switching period may be based on the number of antennas, UE bandwidth, or other measures of UE capabilities.

[0082] Figure 8 8 is a schematic diagram 800 illustrating a downlink reception period 802 according to aspects of the present disclosure. The downlink reception period 802 starts from the symbol immediately following the control resource set (CORESET) / PDCCH symbol 804 and extends to the last downlink symbol of the downlink time slot or the last guard symbol 806 of the special (S) time slot (see Slot 3) on the configured carrier.

[0083] As pointed out above, Figure 4A-8 is provided as an example. Other examples may differ from those described above. Figure 4A-8 Descriptive.

[0084] Fig. 9 9 is a diagram illustrating an example process 900 performed, for example, by a user equipment (UE) according to various aspects of the present disclosure. For example, the UE may be a reduced capability UE, such as an NR light or Internet of Things (IoT) device. In block 902, the process 900 receives a receive (Rx) chain switching configuration for a multi-carrier environment from a base station. For example, the Figure 5A-8 The Rx switching gap is configured as shown in .

[0085] At block 904, process 900 utilizes a plurality of receive chains to receive a physical downlink control channel (PDCCH) on one or more carriers in a multi-carrier environment according to a receive chain switching configuration. Figure 5A As shown in , in time slots 0 and 1, TDD carrier 1 receives a PDCCH for scheduling a PDSCH on TDD carrier 1 according to a cross-scheduling Rx switching configuration (502). In some aspects, the process may receive a PDCCH simultaneously on multiple carriers, with one receive chain assigned to each carrier. For example, as shown in reference Figure 5B As discussed, in time slot 0, the UE simultaneously receives PDCCH on two carriers (eg, TDD carrier 1 and TDD carrier 2), with one receive chain on TDD carrier 1 and one receive chain on TDD carrier 2.

[0086] In block 906, the process decodes downlink control information (DCI) from the PDCCH for physical downlink shared channel (PDSCH) scheduling across multiple carriers in a multi-carrier environment. Figure 5A As shown, TDD carrier 1 uses two Rx antennas to receive the PDCCH for scheduling the PDSCH spanning both TDD carrier 1 and TDD carrier 2. Figure 5B As shown at time slot 0 in FIG. 1 , TDD carrier 1 and TDD carrier 2 each receive a PDCCH for scheduling a PDSCH in TDD carrier 1 using one Rx antenna.

[0087] In block 908, the process performs receive chain switching based at least in part on the PDSCH scheduling and Rx switching configuration from the decoded DCI. In some aspects, the receive chain switching may include switching one or more of the receive chains to the second carrier during the switching period if the downlink time slot of the first carrier overlaps with the downlink time slot of the second carrier. For example, Figure 8 As shown in , the switching period may include one or more symbols at the beginning of the downlink reception period of the configured carrier and one or more symbols at the end of the downlink reception period of the configured carrier.

[0088] Furthermore, in some aspects, when a downlink reception period of a first carrier overlaps an uplink time slot of a second carrier, multiple receive chains may be maintained on the current carrier. Fig. 6A As shown in time slot 4, the downlink time slot of TDD carrier 1 overlaps with the uplink time slot of TDD carrier 2, so no carrier switching period is configured.

[0089] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the various aspects.

[0090] As used, the term "component" is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. As used, a processor is implemented with hardware, firmware, and / or a combination of hardware and software.

[0091] Some aspects are described in conjunction with a threshold. As used, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0092] It will be apparent that the described systems and / or methods can be implemented in various forms of hardware, firmware, and / or combinations of hardware and software. The actual specialized control hardware or software code used to implement these systems and / or methods is not a limitation of the various aspects. Therefore, the operation and behavior of the systems and / or methods are described without reference to specific software code, it being understood that software and hardware can be designed to implement the systems and / or methods based at least in part on the description.

[0093] Even if the specific combination of features is recorded in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features can be combined in a manner that is not specifically recorded in the claims and / or specifically disclosed in the specification. Although each dependent claim listed below may only be directly subordinate to one claim, the disclosure of various aspects includes the combination of each dependent claim with each other claim in the claim set. The phrase "at least one of" referring to the list of items refers to any combination of those items, including a single member. For example, "at least one of a, b or c" is intended to cover a, b, c, ab, ac, bc and abc, and any combination with multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc and ccc or any other ordering of a, b and c).

[0094] The elements, actions or instructions used should not be interpreted as key or necessary unless explicitly described as such. In addition, as used, the articles "a" and "an" are intended to include one or more items and can be used interchangeably with "one or more". In addition, as used, the terms "set" and "group" are intended to include one or more items (e.g., related items, unrelated items, combinations of related items and unrelated items, etc.), and can be used interchangeably with "one or more". In the case of only one item expected, the phrase "only one" or similar language is used. In addition, as used, the terms "has", "have", "containing", etc. are intended to be open terms. In addition, unless otherwise explicitly stated, the phrase "based on" is intended to mean "based at least in part on".

Claims

1. A method of wireless communication performed by a user equipment (UE), comprising: receiving, from a base station, a receive chain switching configuration for a multi-carrier environment; utilizing a plurality of receive chains according to the receive chain switching configuration to receive a physical downlink control channel (PDCCH) on at least one carrier of the multi-carrier environment; decoding downlink control information (DCI) from the PDCCH for physical downlink shared channel (PDSCH) scheduling across multiple carriers in the multi-carrier environment; as well as Receive chain switching is performed based at least in part on the PDSCH schedule from the decoded DCI and the receive chain switching configuration.

2. The method according to claim 1, wherein: The at least one carrier comprises a single carrier.

3. The method according to claim 2, wherein: Performing the receive chain switching includes switching at least one of the receive chains to the second carrier during a switching period when a downlink timeslot of the first carrier overlaps with a downlink timeslot of the second carrier.

4. The method according to claim 3, wherein: The switching period includes one or more symbols at the beginning of a downlink reception period of the configured carrier and one or more symbols at the end of the downlink reception period of the configured carrier.

5. The method according to claim 2, further comprising: When a downlink reception period of the first carrier overlaps with an uplink time slot of the second carrier, the plurality of reception chains are maintained on the current carrier.

6. The method according to claim 1, wherein: The at least one carrier includes the plurality of carriers, the method further comprising: simultaneously receiving the PDCCH on the plurality of carriers, wherein one receive chain is allocated to each carrier.

7. The method according to claim 6, further comprising: At least one of the receive chains is switched to the second carrier during the switching period unless a rank-one PDSCH is simultaneously scheduled for both carriers during the downlink reception period.

8. The method according to claim 7, wherein: When the downlink time slot of the first carrier overlaps with the downlink time slot of the second carrier, the switching period includes one or more symbols in front of the configured downlink reception period of the carrier and one or more symbols in the last of the configured downlink reception period of the carrier.

9. The method according to claim 7, wherein: When a downlink timeslot of a first carrier overlaps with an uplink timeslot of the second carrier, the switching period includes the last one or more symbols of the downlink timeslot of the first carrier.

10. The method according to claim 1, further comprising: A frequency position configuration of a switching period is semi-statically received via one carrier of the multi-carrier environment.

11. The method according to claim 1, further comprising: When a downlink time slot of a first carrier overlaps with a special time slot of a second carrier, at least one of the receive chains is switched to the second carrier during a switching period.

12. The method according to claim 11, wherein: The switching period includes one or more symbols preceding the downlink reception period.

13. The method according to claim 1, wherein: The downlink reception period starts at the first symbol after a CORESET (Control Resource Set) or PDCCH symbol and ends at the last symbol of a downlink slot on a carrier configured by the base station.

14. The method according to claim 1, wherein: The downlink reception period starts at the symbol after the CORESET / PDCCH symbol and ends at the last guard symbol of the special slot on the carrier configured by the base station.

15. An apparatus for wireless communication by a user equipment (UE), comprising: Memory; as well as at least one processor coupled to the memory, the at least one processor configured to: receiving, from a base station, a receive chain switching configuration for a multi-carrier environment; utilizing a plurality of receive chains according to the receive chain switching configuration to receive a physical downlink control channel (PDCCH) on at least one carrier of the multi-carrier environment; decoding downlink control information (DCI) from the PDCCH for physical downlink shared channel (PDSCH) scheduling across multiple carriers in the multi-carrier environment; as well as Receive chain switching is performed based at least in part on the PDSCH schedule from the decoded DCI and the receive chain switching configuration.

16. The device according to claim 15, wherein: The at least one carrier comprises a single carrier.

17. The device according to claim 16, wherein: The at least one processor is further configured to switch at least one of the receive chains to a second carrier during a switching period when a downlink timeslot of a first carrier overlaps with a downlink timeslot of a second carrier.

18. The device according to claim 17, wherein: The switching period includes one or more symbols at the beginning of a downlink reception period of the configured carrier and one or more symbols at the end of the downlink reception period of the configured carrier.

19. The device according to claim 16, wherein: The at least one processor is further configured to maintain the plurality of receive chains on the current carrier when a downlink reception period of the first carrier overlaps with an uplink timeslot of the second carrier.

20. The device according to claim 15, wherein: The at least one carrier includes the plurality of carriers, and the at least one processor is further configured to simultaneously receive the PDCCH on the plurality of carriers, wherein one receive chain is allocated to each carrier.

21. The device according to claim 20, wherein: The at least one processor is further configured to switch at least one of the receive chains to a second carrier during a switching period unless a rank-one PDSCH is concurrently scheduled for both carriers during a downlink reception period.

22. The device according to claim 21, wherein When the downlink time slot of the first carrier overlaps with the downlink time slot of the second carrier, the switching period includes one or more symbols in front of the configured downlink reception period of the carrier and one or more symbols in the last of the configured downlink reception period of the carrier.

23. The device according to claim 21, wherein When a downlink timeslot of a first carrier overlaps with an uplink timeslot of the second carrier, the switching period includes the last one or more symbols of the downlink timeslot of the first carrier.

24. The device according to claim 15, wherein: The at least one processor is further configured to semi-statically receive a frequency position configuration of a switching period via one carrier of the multi-carrier environment.

25. The device according to claim 15, wherein: The at least one processor is further configured to switch at least one of the receive chains to a second carrier during a switching period when a downlink timeslot of a first carrier overlaps a special timeslot of a second carrier.

26. The device according to claim 25, wherein The switching period includes one or more symbols preceding the downlink reception period.

27. The device according to claim 15, wherein: The downlink reception period starts at the first symbol after a CORESET (Control Resource Set) or PDCCH symbol and ends at the last symbol of a downlink slot on a carrier configured by the base station.

28. The device according to claim 15, wherein: The downlink reception period starts at the symbol after the CORESET / PDCCH symbol and ends at the last guard symbol of the special slot on the carrier configured by the base station.

29. An apparatus for wireless communication by a user equipment (UE), comprising: means for receiving, from a base station, a receive chain switching configuration for a multi-carrier environment; means for receiving a physical downlink control channel (PDCCH) on at least one carrier of the multi-carrier environment utilizing a plurality of receive chains according to the receive chain switching configuration; means for decoding downlink control information (DCI) from the PDCCH for physical downlink shared channel (PDSCH) scheduling across multiple carriers in the multi-carrier environment; as well as Means for performing receive chain switching based at least in part on the PDSCH schedule from a decoded DCI and the receive chain switching configuration.

30. The device according to claim 29, wherein: The at least one carrier comprises a single carrier, and the apparatus further comprises means for switching at least one of the receive chains to a second carrier during a switching period when a downlink timeslot of the first carrier overlaps with a downlink timeslot of the second carrier.

31. The device according to claim 30, wherein The switching period includes one or more symbols at the beginning of a downlink reception period of the configured carrier and one or more symbols at the end of the downlink reception period of the configured carrier.

32. The apparatus of claim 30, further comprising: Means for maintaining the plurality of receive chains on a current carrier when a downlink receive period of the first carrier overlaps an uplink timeslot of a second carrier.

33. The device according to claim 29, wherein: The at least one carrier includes the multiple carriers, and the device also includes: a unit for simultaneously receiving the PDCCH on the multiple carriers, wherein one receive chain is assigned to each carrier; and a unit for switching at least one of the receive chains to a second carrier during a switching period unless a rank-one PDSCH is scheduled simultaneously for two carriers during a downlink reception period.

34. The device according to claim 33, wherein When the downlink time slot of the first carrier overlaps with the downlink time slot of the second carrier, the switching period includes one or more symbols in front of the configured downlink reception period of the carrier and one or more symbols in the last of the configured downlink reception period of the carrier.

35. The device according to claim 33, wherein When a downlink timeslot of a first carrier overlaps with an uplink timeslot of the second carrier, the switching period includes the last one or more symbols of the downlink timeslot of the first carrier.

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